This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A335691 #10 Jul 20 2020 16:23:19 %S A335691 1,0,1,4,81,1936,70225,3437316,220017889,17821182016,1782120871521, %T A335691 215636596084900,31051670188655281,5247732257301156624, %U A335691 1028555522495168900401,231424992560450869558756,59244798095490816735545025,17121746649596584336387952896 %N A335691 A000166(n)^2. %D A335691 I. Kaplansky and J. Riordan, The problème des ménages, Scripta Math. 12, (1946), 113-124. See p. 115. %H A335691 I. Kaplansky and J. Riordan, <a href="/A000166/a000166_1.pdf">The problème des ménages</a>, Scripta Math. 12, (1946), 113-124. [Scan of annotated copy] %Y A335691 Cf. A000166, A335692, A335693. %K A335691 nonn %O A335691 0,4 %A A335691 _N. J. A. Sloane_, Jul 20 2020